Gas burner



May 17, 1938. o. LUTHERER GAS BURNER Filed ApIil 25, 1934 INVENTOR GASOTTO LUTHERER Patented May 17, 1938` APATENT oFFicE GAS BURNER.

Otto Lutherer, Cleveland, Ohio, assigner to The North AmericanManufacturing Company, i Cleveland, Ohio, a corporation of Ohio lApplication April 25, 1934,` Serial No. 722,339

l Claims.

This invention relates to burners for gaseous fuels wherein combustionis characterized by a luminous flame. The combustible constituentstypically em- 5 ployed in such va burner-are usually the availablenatural or artificial gas hereinafter referred to as gas or merely fuel,and a suitable supporter of combustion therefor, usually air, andhereinafter so referred to; although it will be appreciated that 1oother gaseous hydrocarbon fuel and suitable supporter of combustiontherefor'may be employed, In some industrial burner applications it hasrecently been considered desirable` thatthe flame have a luminouscharacteristic, by which some of its heat may be distributed to the workby radiation. Heretofore in the art it has .been considered `necessaryto this end, that very close regulation be maintained, of relativeyvelocities of the combustible constituents and of the rate and manner 2oof their commingling, it being considered essential that combustion beata slow rate, confined to a `limited zone of contact between adjacentconfluent streams of gas and air.`

Objects of this invention are to produce means by which luminouscombustion may be had without critical sensitivity of such operatingconditions.

Luminous combustion is obtained according to this invention, by crackingor breaking down of ther gas by heat, without combustion, to liberateminute particles of free carbon, which subsequently, during combustion,become incandescent; the invention being based upon the theory that heatonly ls required to crack the gas, so that its subsequent incandescenceis not primarily a function of time or of its manner of joining the airof combustion, and hence the invention `does not contemplate'theusualattempt to prevent .or delay or particularly control intermin- 40 glingof the air with the gas, the latter having been cracked.

More particular objects of the invention are therefore to provide forthe liberation of free carbon particles within the burner itself and inamount easily controlled by control of the amount the gas is preheated.The burner `contemplated by the invention includes means for sopreheating the gas, by auxiliary combustion, independent of the primarycombustion accomplished by "the burner, the auxiliary combustion beingeither of an independent fuel or of a portion of the gas Y with whichthe burner is supplied.

The exact nature of this invention together with further objects andadvantages thereof will be apparent from the following description takenin connection with the accompanying drawing which is, generally, atypical longitudinal section through a characteristic embodimentthereof.

With reference now to the drawing,r `I represents the wall of anindustrialfurnace, having a 5 burner inlet opening 2, and the usualcover plate or jacket 3.

Secured to the outer end of the openingZ as by the bolts 4. is a burnergenerally indicated at 5, The burner includes a central tubularduct or10 pipe 6, the outer end of which is adapted for connection with a gassupply as indicated, The duct ls preferably longitudinally adjustablerelative to other parts of the burner and, as shown for the purpose, issecured in slidably adjusted positions 15 by a set screw 1 in theclosure 8 in which the duct bears. 'I'he burner includes a casingproviding cavity 9 about the duct 6 having the lat'eralconnection IIifor a source of `air supply. A baille II extending into the cavity 9about the duct 6 in 20 the zone of the connection I0 forms an annularpassage I2 about the duct and provides a uniform air ow along thepassage I2 from the air inlet. About the passage I2 is the jacketindicated providing an annular chamber I3 having connection 25 as at I4for a source of auxiliary fuel; and a number of circumferentially spacedopenings I5 allow .flow of fuel from the chamber I3 to the passage I2and about the duct 6.

It will be appreciated that all the burner'parts r3o described, with theexception of the supply connections referred to, may be of circularsection and coaxially arranged as indicated; and that the opening v2 inthe furnace wall is formed as indicated, to provide acon'tinuation ofthe discharge opening of the burner; but other sectional forms of theparts may be preferable in specific applications.

In yoperation of the burner air is supplied through the connection I0,the fuel gas through 40 the duct 6 and an auxiliary gaseous fuel throughthe connection Il, all as indicated bythe legends on the drawing, eachunder sufficient pressure to accomplish its feeding, and preferably eachunder suitable volumetric control as by the usual valve 45 means.

'I'he air entering the chamber 9 is evenly distributedl by the baille IIso that it flows through the passage I2 as a stream of annular sectionalong and about the duct 6, thence lthrough the 50 furnace wall opening2, and ultimately into the furnace. The auxiliary fuel is distributed bythe annular chamber I3 and finds its way into the passage I2 through theopenings I5, forming a ring of 55 jets about the duct l. Combustion ofthis auxiliary fuel at these jets heats the ductv l to a hightemperature, controlled by the amount of auxiliary fuel fed to the jets.'Ihe amount of air flowing through the passage l2 is very much in excessof that necessary to support complete combustion of the auxiliary fuelat the jets. `In fact it may in some cases be desirable that a certainamount of air be included with the auxiliary fuel supplied to its inletconnection i4.A At any rate, there issues from the passage l2 into theopening 2, suilicient air to support complete combustion of gasdischarged by the mouth 6a of the duct, including however the productsof combustion of the jets at the openings I5.

vThe gas flowing through the duct 6 is cracked or-broken down by thetemperature towhich the duct is raised bythe auxiliary fuel jets, sothat the gas leaving the mouth 6a of the duct, acting as a nozzle,includes, entrained, the minute carbon particles liberated by thecracking process. As the gas leaves the duct and mingles with the airits combustion takes place, the combustion of the entrained carbonparticles being accompanied by their incandescence so that the flame hasa luminous character.

While this luminous combustion might theoretically commence close to theend 8a of the gas duct, it will be relatively slow, continuing throughthe opening 2 in the furnace wall and therebeyond, most of the flameextending into the interior of the furnace, as will be appreciated byone familiar with the art, and the hollow of the opening 2 actingprimarily as a mixing chamber. By longitudinal adjustment of the nozzleor gas duct 6 its mouth 6a may be so positioned that the flame will besubstantially whollywithin the furnace cavity. By the arrangementdescribed, the greater the amount of heat' supplied by the auxiliaryfuel, which heat is easily controlled by control of the auxiliary fuelitself, the higher will be the temperature to which the gas in the duct6 will be heated and the greater will be the degree ofits cracking..Thus the degree of carbon liberation can be controlled independent ofthe furnace temperature.

Also, the proper functioning of the burner is substantiallyindependentof gas and air velocities through the burner and of the rate of mix-Ving ofthe gas and airafter they have passed from the burner into thefurnace.

' What I claim is:

1. In a gas burner of the class described, pipe meansiarranged todeliver fuel at one end, casing means arranged to provide a chamberabout said pipe means, with an end opening in the direction of flow inthe pipe means and with its opposite end closed, said casing having alateral air inlet adjacent its closed end, annular baille means arrangedopposite said inlet. with an end opening in the direction of the closedcasing end but short of the latter. said pipe means being mounted uponsaid casing end, and means including an opening in said casing means forfeeding auxiliary fuel to said chamber about said pipe means.

2. In a gas burner of the class described, a straight pipe arranged todeliver gas at one end, casing means arranged to provide a chambercoaxially disposed about said pipe, with an end opening in the directionof flow in the pipe and with its opposite end closed, means for feedingauxiliary fuel to said chamber distributed about said pipe, and meansfor feeding air to said chamber adjacent the closed end of the latter,in suiilcient amount to supportcombustion of both of said fuels, andbaille means arranged coaxially within said chamber to distribute saidair uniformlynbout saidpipe before contact of said air with either ofsaid fuels.

3. In a gas burner of the class described, a straight pipe arrangedto'deliver gas at one end, casing means arranged to provide a coaxialchamber about said pipe, with van open end adjacent the mouth of saidpipe and with its opposite end closed, means for feeding auxiliary fuelto said chamber intermediate the ends thereof and distributed about saidpipe, said casing means having a lateral air inlet adjacent its closedend and baille means coaxially arranged opposite said inlet to providedistribution of air about said pipe before contact with said auxiliaryfuel.

4. In a gas burner of the class described, a straight pipe arranged todeliver gas at one end, casing means arranged to provide a coaxialchamber about said pipe, with an end opening in the direction of flow inthe pipe and with its op posite end closed,saidy casing having a lateralair inlet adjacent its closed end, baille means arranged opposite saidinlet to direct infiowing air toward the closed end of said chamber,thence toward the mouth of said pipe, and means for feeding auxiliaryfuel to said chamber about said pipe, between said pipe mouth and saidbaille means. y

5. Agas burner of the class described comprising a, straight main fuelpipe having an open mouth, casing means arrangedA to provide a chambercoaxial with said pipe, with an end opening in the direction of flow inthe pipe and with its opposite end closed about the pipe, said pipeextending into said chamber, said casing means having a lateralair inletopening and baffle means arranged to direct incoming air toward saidclosed chamber end and about said pipe, and means for feeding auxiliaryfuel about said pipe within s'aid chamber.

OTTO LUTI-IERER.

